Backpacking stove

ABSTRACT

A burning appliance having a burner assembly including a burner for providing combustion is disclosed. The appliance includes a fuel tip for supplying fuel to the burner assembly and a fuel control and cleaning assembly cooperating with the fuel tip to permit control of fuel supplied to the burner and cleaning of the fuel tip while the appliance is in operation. The cleaning assembly may be formed on the appliance itself and may incorporate a cleaning element, a cleaning element control mechanism and a heat dissipating interface positioned with respect to the cleaning element and the cleaning element control mechanism such that a user may control the cleaning element with the cleaning element control mechanism without the use of gloves or other protective equipment while the appliance is in operation.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to fuel burning appliances, and morespecifically to backpacking and camping stoves.

BACKGROUND OF THE INVENTION

Fuel burning camp stoves and lanterns for camping and outdoor use arewell known and are described, for example, in U.S. Pat. No. 3,876,364,which is owned by The Coleman Company, Inc., assignee of the presentinvention. Liquid fuel, which is often used in such camp stoves andlanterns, may be, for example, COLEMAN branded fuel, white gas, unleadedgasoline, or other liquid fuels.

In some conventional liquid fuel camp stoves such as the ones which TheColeman Company, Inc. has offered for many years, fuel is contained in apressure vessel or fuel tank into which air is pumped under pressure. Asdescribed in U.S. Pat. No. 3,876,364, the fuel tank is equipped with adip tube which extends to nearly the bottom of the tank. The dip tube isclosed at the bottom with the exception of a small diameter orificethrough which fuel is allowed to enter. The dip tube has an internalconduit which is open at the bottom and which communicates with theupper part of the pressure vessel above the maximum intended fuel level.The dip tube orifice can be partly blocked by insertion of a needle,which is suitably connected to the fuel control system. The needlepartly blocks the orifice during the lighting cycle and is removed toleave the orifice unblocked during the normal burn cycle. This partialblockage during the lighting cycle causes air to be drawn down the spacebetween the internal and outer conduits of the dip tube from an openingat the upper part of the pressure vessel. As this air accompanies fuelup the internal conduit, a fuel-lean mixture of fuel and air is createdto enhance lighting. A fuel-lean mixture is needed at initial lighting,because the fuel in the mixture is not vaporized and thus must be mixedwith a lot of air for combustion. The air-fuel mixture then passes to agenerator which is connected to the dip tube by the fuel control system.The generator is a metal tube which passes above the burner of the stoveinto a venturi assembly which is connected to the burner. The generatoris heated by the flame of the burner when the burner is operating. Fuelis discharged at high velocity from an orifice or jet at the end of thegenerator into the venturi where air is aspirated and mixed and fed tothe burner with the air/fuel mixture as a combustible mixture forburning.

After the burner has been operating for an initial period and thegenerator is sufficiently heated, the fuel that travels through thegenerator is vaporized. As such, after the generator is heated, the fuelexpands and may be supplied in a less lean mixture. At this point, theneedle may be removed from blocking of the passage.

In U.S. Pat. No. 3,876,364, the restricting needle is operated byrotating a fuel control knob. In other appliances, a lever is used toadjust the appliance for starting and running. The lever is moved up tostart and then down to run.

The foregoing structure for allowing liquid fuel appliances to belighted when the generator is cold is referred to as an “instantlighting system.” Liquid fuel appliances, which do not include aninstant lighting system require some other means for heating thegenerator during start-up, for example, liquid priming fuel, heatingpaste, or a priming pad typically made of a high temperature ceramicmaterial. In any event, the lighting process requires some form ofpreheating.

This is true for fuel burning camping and backpack stoves having what isknown in the art as an impingement burner. Some such stoves havingimpingement burners are capable of operating on a number of fuel sourcesin addition to the liquid fuels discussed above. In general, such stovesare considered multi-fuel camping and/or backpacking stoves. Generallyspeaking, these multi-fuel stoves can burn liquid fuel, propane, butane,kerosene, and various propane/butane mixtures, among others.

An advantage of the multi-fuel camping and/or backpacking stoves overthe above-described liquid fuel stoves centers around the available fuelsources in the region of the world in which the stove will be used. Forthe adventure camping market, hikers, climbers, and other adventurerstypically travel to various remote locations to undertake their nextclimbing, hiking or other challenge. Unfortunately, the available fuelsupply will depend upon what is available in the given locality.Accordingly, a multi-fuel stove is the ideal tool for such enthusiasts.

Existing multi-fuel stoves do, however, have limitations. Because of,among other things, their design and ability to run on multiple fuelsources, the ability to have precise control of the flame and thus theheat output of the stove is limited. In addition, complex fuel tipcleaning systems are generally employed with such multi-fuel stoves.Because of the nature and design of the cleaning systems, adequatecleaning of the fuel tip cannot be achieved unless the stove is turnedoff, and depending upon the situation, allowed to cool.

What is needed therefore, but presently unavailable in the art is amulti-fuel fuel burning appliance, such as, but not limited to, acamping and backpacking stove, lantern, torch or other device having afuel tip that can be cleaned while the device is still running. Morespecifically, what is needed is a multi-fuel device having a cleaningneedle or other element that functions to both clean the fuel tip andcontrol the fuel path, thus providing flame and heat control at theburner. More preferably, such a stove should be designed so that theuser can perform both of these functions while the stove is operatingand with a bare hand, i.e., without any special protective gear, such asgloves. The control for such functionality should be a component of thestove and not a feature of the fuel tank or fuel supply line or fuelsupply valves, but should not significantly increase the size orcomplexity of the stove. It is to the provision of such a multi-fuelstove that the present invention is primarily directed.

SUMMARY OF THE INVENTION

The following presents a simplified summary of some embodiments of theinvention in order to provide a basic understanding of the invention.This summary is not an extensive overview of the invention. It is notintended to identify key/critical elements of the invention or todelineate the scope of the invention. Its sole purpose is to presentsome embodiments of the invention in a simplified form as a prelude tothe more detailed description that is presented later.

In accordance with an aspect of the invention, a burning appliance isprovided having a burner assembly including a burner for providingcombustion and a fuel tip for supplying fuel to the burner assembly. Afuel control and cleaning assembly may cooperate with the fuel tip topermit control of fuel supplied to the burner and cleaning of the fueltip while the stove is in operation.

In accordance with another aspect of the invention, a multi-fuel burningappliance capable of running on any one of a number of fuels isprovided. The multi-fuel burning appliance includes a burner assemblyhaving a burner for providing combustion and a fuel tip for supplyingfuel to the burner assembly. A cleaning assembly is constructed andarranged on the burning appliance to control the amount of fuel suppliedto the burner while at least partially cleaning the fuel tip duringstove operation.

In accordance with yet another aspect, a cleaning assembly for a burningappliance is provided. The cleaning assembly is preferably affixed tothe burning appliance and may include a cleaning element, a cleaningelement control mechanism and a heat dissipating interface positionedwith respect to the cleaning element and the cleaning element controlmechanism such that a user may control the cleaning element with thecleaning element control mechanism without the use of gloves or otherprotective gear while the appliance is in operation.

In yet another aspect of the invention, the present invention isdirected to a method of controlling the fuel supply through the fuel tipof a multi-fuel burning appliance while facilitating at least partialcleaning of the fuel tip while the burning appliance is in operation.

Additional features and advantages of the invention will be set forth inthe detailed description which follows and in part will be readilyapparent to those skilled in the art from that description or recognizedby practicing the invention as described herein.

It is to be understood that both the foregoing general description andthe following detailed description are merely exemplary of theinvention, and are intended to provide an overview or framework forunderstanding the nature and character of the invention as it isclaimed. The accompanying drawings are included to provide furtherunderstanding of the invention, illustrate various embodiments of theinvention, and together with the description serve to explain theprinciples and operation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of a stove together with a fuel tank inaccordance with an embodiment of the invention;

FIG. 2 is a top view of some of the components of the stove depicted inFIG. 1;

FIG. 3A is an exploded side perspective view of the stove depicted inFIG. 1;

FIG. 3B is a side perspective view of the stove depicted FIG. 3A in anassembled expanded configuration;

FIG. 3C is a side perspective view of the stove depicted in FIG. 3A inan assembled collapsed configuration;

FIG. 4A is a side perspective view of the cleaning valve assembly of thestove depicted in FIG. 1;

FIG. 4B is an end view of the cleaning valve assembly depicted in FIG.4A;

FIG. 4C is a cross-sectional view of the cleaning valve assembly of FIG.4B taken along lines A-A;

FIG. 4D is a partial cross-sectional view of the cleaning valve assemblyof FIG. 4C showing the cleaning element and fuel tip cooperating toprovide a low fuel flow state; and

FIG. 4E is a partial cross-sectional view of the cleaning valve assemblyof FIG. 4C showing the cleaning element and fuel tip cooperating toprovide a high fuel flow state.

DETAILED DESCRIPTION

In the following description, various embodiments of the presentinvention will be described. For purposes of explanation, specificconfigurations and details are set forth in order to provide a thoroughunderstanding of the embodiments. However, it will also be apparent toone skilled in the art that the present invention may be practicedwithout the specific details. Furthermore, well-known features may beomitted or simplified in order not to obscure the embodiment beingdescribed.

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawing figures. Wherever possible, the same referencenumerals will be used throughout the drawings to refer to the same orlike parts. An exemplary burning appliance of the present invention isshown in FIG. 1 as a backpacking stove and is designated generallythroughout by reference numeral 20.

In the embodiment shown, the stove 20 includes a burner assembly 22connected by a fuel feed line 24 to a liquid fuel tank 26. The liquidfuel feed line 24 connects to a generator 27, which in turn is connectedto a valve assembly, preferably a cleaning valve assembly 28. Thegenerator 27, in a manner known in the art, winds around and over theburner assembly 22 so that it may be heated by a flame produced at theburner, preferably an impingement burner 30. The generator 27 thenextends downward to a bottom of the stove 20 and into one side of thecleaning valve assembly 28.

As configured in accordance with this embodiment of the invention, thegenerator 27 and/or portion of the cleaning valve assembly 28 must bepre-heated so that fuel supplied through the generator 27 to thecleaning valve assembly 28 will become hot enough to vaporize so thatignition and combustion can occur. As can be seen in FIG. 2, a burnersupport assembly 32 is positioned below the burner assembly 22, andsupports the cleaning valve assembly 28 and a preheating pad 34 locatedbeneath and around the cleaning valve assembly 28. Preheating pad 34, ispreferably made of a high temperature ceramic material and may besaturated with liquid fuel, alcohol or some other fuel source that canbe ignited and burned to create sufficient heat over several minutes inorder to cause at least partial vaporization of the fuel in the portionof cleaning valve assembly 28 and generator 27, thereby allowingignition of the fuel discharged through an exit orifice 36 of fuel tip38 located at a top portion of the cleaning valve assembly 28 beneathburner 30 of burner assembly 22.

Turning now to FIG. 3A, an exploded perspective view of stove 20 of thepresent invention is depicted. Burner assembly 22 including burner 30 isaffixed to the burner support assembly 32, preferably via a treadedconnection on the top of the cleaning valve assembly 28 adjacent thefuel tip 38. Burner support assembly 32 is preferably connected to astove housing 40, to which a plurality of legs 42 are pivotallyattached. As shown in FIG. 3C, the legs 42 are thus permitted to berotated in and out of engagement with the housing 40 so that the stovemay be compacted for ease of packing and or transport.

FIG. 3B depicts the stove 20 shown in FIG. 3A in an assembledconfiguration with the legs 42 extended, while FIG. 3C depicts the stove20 of FIG. 3A in a collapsed configuration with the legs 42 adjacent thehousing 40.

The details of the novel cleaning valve assembly 28 are depicted in FIG.4A through FIG. 4E. As depicted in FIG. 4A, cleaning valve assembly 28preferably includes a valve housing 44 to which fuel tip 38 is attached.Positioned within orifice 36 of fuel tip 38 is a cleaning element,preferably a cleaning needle 46 (FIG. 4C). The needle 46 may becontrolled by a control lever 48, which extends from the valve housing44 to and out a remote lever housing 50. As shown in FIG. 4B, lever 48extends centrally through lever housing 50. In conventional stoves, allcomponents of the valve assembly are generally made of brass, which isknown for its high heat conduction properties. When conventional stovesincorporate cleaning needles in these brass valve assemblies, the valveassembly becomes to hot to handle during stove operation, and thus thecleaning needle cannot be used while the stove is combusting fuel.Because the cleaning needle cannot be used during operation ofconventional multi-fuel stoves, it has not been used to control fueloutput from the fuel tips of such stoves. Instead, fuel flow and/orpressure has generally been controlled at the fuel tank or fuel cylinderby valves upstream of the fuel supply line. As a result, limited flameand burner control can be achieved, and the stoves are not expected tohave significant flame and heat adjustability.

In accordance with a preferred embodiment of the present invention,fine-tuning flame adjustability is achieved with the use of a novel heatdissipating element, preferably a heat dissipating interface 52positioned between the valve housing 44 and lever housing 50. In apreferred embodiment, the heat dissipating interface is a tubular membermade of a low heat conducting material such as, but not limited to, aceramic material, titanium or preferably stainless steel. As shown inFIG. 4C, lever 48 passes through lever housing 50 through heatdissipating interface 52 and into valve housing 44.

As seen in FIG. 4C, lever 48 preferably has a bent end 54 thatcooperates with a cleaning needle housing 56 that houses the cleaningneedle 46 that preferably measures between 0.02 (two-hundredths) and0.005 (five-thousandths) of an inch in diameter, and most preferably0.009 (nine-thousandths) of an inch in diameter. When lever 48 isrotated, bent end 54 of lever 48 takes an eccentric path that forms acam in connection with the cleaning needle housing 56 that elevates andlowers cleaning needle 46 within the orifice 36 of fuel tip 38.

The movement within the orifice 36 has at least two functions. First, itcleans deposits from the walls of fuel tip 38 in orifice 36 that areleft behind as a result of fuel passage and products of combustion.Second, and as shown clearly in FIGS. 4D and 4E, the cleaning needle 46changes the amount of fuel flow (as well as other attributes) throughorifice 36 as it moves into and out of orifice 36 depending upon theposition of lever 48. The inside of fuel tip 38 is preferably neckeddown and may incorporate one or more gaskets in order to reduce thevolume of fuel that may pass through orifice 36 as cleaning needle 46moves up into fuel tip 38. Generally speaking, the optimum clearancebetween the cleaning needle and the walls of the fuel tip 38 should beat least about 0.002 (two-thousandths) of an inch.

The heat dissipating aspects of the present invention are preferablyprovided by heat dissipating interface 52. More preferably, the entirelength of lever 48 is also made from a low heat conducting material suchas a ceramic material, titanium, stainless steel, or some combinationthereof. The same is preferably also true for cleaning needle 46. As aresult of the heat from burner assembly 22, the body of stove 20generally runs about 500 to 600 degrees F. If all of the above-mentionedcomponents were made of high heat conducting materials such as brass,the temperature of the end of the lever would be very close to thetemperature of the body of the stove 20. In accordance with the presentinvention, and in a preferred embodiment of the invention where lever48, cleaning needle 46 and heat dissipating interface 52 are allstainless steel and the length of heat dissipating interface 52 isapproximately one and one-quarter inches long, lever housing 50 isapproximately two-hundred (200) degrees F. and the end of the lever isapproximately room temperature when the body of stove 20 is betweenfive-hundred (500) and six-hundred (600) degrees F. and the stove isrunning. The longer the length of heat dissipating member 52, the lessheat that is transferred to the end of lever 48. One of ordinary skillin the art will recognize that not all of the above-mentioned elementsneed to be made of low heat conductive material in order to reduce theheat transfer to the end of lever 48. Other combinations orconstructions may be equally effective and are intended to be covered bythis disclosure. Generally speaking, the length of heat dissipatinginterface 52 should be at least one (1) cm in length, preferably one (1)inch in length, and most preferably, greater that one and one-quarter(1¼) inches in length. The increased length itself assists withdissipation as does the additional surface area exposed to ambient airaround that surface area.

Other variations are within the spirit of the present invention. Thus,while the invention is susceptible to various modifications andalternative constructions, a certain illustrated embodiment thereof isshown in the drawings and has been described above in detail. It shouldbe understood, however, that there is no intention to limit theinvention to the specific form or forms disclosed, but on the contrary,the intention is to cover all modifications, alternative constructions,and equivalents falling within the spirit and scope of the invention, asdefined in the appended claims.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. The term “connected” is to beconstrued as partly or wholly contained within, attached to, or joinedtogether, even if there is something intervening. Recitation of rangesof values herein are merely intended to serve as a shorthand method ofreferring individually to each separate value falling within the range,unless otherwise indicated herein, and each separate value isincorporated into the specification as if it were individually recitedherein. All methods described herein can be performed in any suitableorder unless otherwise indicated herein or otherwise clearlycontradicted by context. The use of any and all examples, or exemplarylanguage (e.g., “such as”) provided herein, is intended merely to betterilluminate embodiments of the invention and does not pose a limitationon the scope of the invention unless otherwise claimed. No language inthe specification should be construed as indicating any non-claimedelement as essential to the practice of the invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventor for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventor expects skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

1. A burning appliance, comprising: a burner assembly having a burnerfor providing combustion; a fuel tip for supplying fuel to the burnerassembly; and a fuel control and cleaning assembly cooperating with thefuel tip to permit control of fuel supplied to the burner, and cleaningof the fuel tip while the stove is in operation.
 2. The burningappliance of claim 1, wherein the appliance comprises a stove.
 3. Theburning appliance of claim 1, wherein the appliance comprises a lantern.4. The burning appliance of claim 1, wherein the fuel tip comprises anorifice through which fuel is supplied to the burner assembly, andwherein the fuel control and cleaning assembly comprises an object thatis movable to vary an amount of blockage of the orifice.
 5. The burningappliance of claim 4, wherein moving the object cleans an inner bore ofthe orifice.
 6. The burning appliance of claim 5, wherein the object isa cleaning needle.
 7. The burning appliance of claim 6, wherein the fuelcontrol and cleaning assembly further comprises a control leverconstructed and arranged to cooperate with the cleaning needle such thatactuation of the control lever causes the cleaning needle to move tovary the amount of blockage.
 8. The burning appliance of claim 7,wherein the fuel control and cleaning assembly further comprises a heatdissipating interface positioned between the control lever and thecleaning needle.
 9. The burning appliance of claim 8, wherein the heatdissipating interface comprises a structure between the control leverand the needle, the structure having sufficient heat dissipatingqualities to dissipate heat from the burner assembly a sufficient amountso that a user may operate the control lever by direct contact with thecontrol lever.
 10. The burning appliance of claim 9, wherein thesufficient heat dissipating qualities comprises the heat dissipatinginterface comprising at least one of stainless steel, a ceramicmaterial, and titanium.
 11. The burning appliance of claim 5, whereinthe fuel control and cleaning assembly further comprises a control leverconstructed and arranged to cooperate with the object such thatactuation of the control lever causes the object to move to vary theamount of blockage.
 12. The burning appliance of claim 11, wherein thefuel control and cleaning assembly further comprises a heat dissipatinginterface positioned between the control lever and the object.
 13. Theburning appliance of claim 12, wherein the heat dissipating interfacecomprises a structure between the control lever and the object, thestructure having sufficient heat dissipating qualities to dissipate heatfrom the burner assembly a sufficient amount so that a user may operatethe control lever by direct contact with the control lever.
 14. Theburning appliance of claim 13, wherein the sufficient heat dissipatingqualities comprises the heat dissipating interface comprising at leastone of stainless steel, a ceramic material, and titanium.
 15. Theburning appliance of claim 14, wherein the heat dissipating interfacecomprises a structure that extends around at least a portion of thecontrol lever.
 16. A burning appliance, comprising: a burner assemblyhaving a burner for providing combustion; a fuel tip for supplying fuelto the burner assembly, the fuel tip comprising comprises an orificethrough which fuel is supplied to the burner assembly; and a fuelcontrol assembly comprising an object that is movable to vary an amountof blockage of the orifice.
 17. The burning appliance of claim 16,wherein the fuel control and cleaning assembly further comprises acontrol lever constructed and arranged to cooperate with the object suchthat actuation of the control lever causes the object to move to varythe amount of blockage.
 18. The burning appliance of claim 17, whereinthe fuel control and cleaning assembly further comprises a heatdissipating interface positioned between the control lever and theobject.
 19. The burning appliance of claim 18, wherein the heatdissipating interface comprises a structure between the control leverand the object, the structure having sufficient heat dissipatingqualities to dissipate heat from the burner assembly a sufficient amountso that a user may operate the control lever by direct contact with thecontrol lever.
 20. The burning appliance of claim 19, wherein thesufficient heat dissipating qualities comprises the heat dissipatinginterface comprising at least one of stainless steel, a ceramicmaterial, and titanium.